Chemotherapy can reactivate the growth of “sleeping” tumor cells

The scientific evidence that indicates that chemotherapy can damage non-tumor cells build up and an international team of researchers has now shown that it can reactivate the growth of tumor cells “sleepers” and the reappearance of cancer of breast.

It has been verified by a team of scientists led by researcher Ramya Ganesan, from Emory University (United States), and the conclusions are published today in the journal Plos Biology.

Their main conclusion: that a standard drug used in chemotherapy damages surrounding non-cancerous cells, which can “wake up” to those that are latent and promote the growth of cancer, a finding that is – according to the researchers – very important to understand the recurrence of cancer and point out new targets to prevent and combat it.

Advances in cancer treatment, including chemotherapy, have dramatically reduced mortality in many types of cancer, including breast cancer, but up to 23 percent of patients experience a recurrence within the first five years.

The treatment is designed to destroy all cancer cells, but some often enter a state of dormancy, in which they stop dividing and do not respond to chemotherapeutic agents, and this reactivation occurs when dormant cells wake up again and begin to divide again, the researchers have noted.

Some studies had already indicated that chemotherapy itself can promote the emergence of lethargy, but the mechanism of this effect is still not clear.

To explore this question, the researchers worked with both a cell model and a mouse model of breast cancer, administering a widely used chemotherapy drug (docetaxel) at physiologically relevant concentrations and found that, even at very low doses, some cells were damaged, while cancer cells were not, and that the treatment induced re-entry of the cell cycle in the cancer cells.

The authors demonstrated that this reactivation of dormant cells was due to the release of two key cell signaling molecules, which acted on these dormant cells to promote their growth, both in vitro and in vivo.

This provided the team with potential cancer targets, and they showed that antibodies that neutralized those two molecules (called G-CSF and IL-6) or a drug that blocked the mediator of those signals within cancer cells inhibited the awakening of the lethargy due to treatment “docetaxel”.

The researchers have stressed that these results have several important implications, as they highlight the importance of surrounding cells, and not just the cancer cells themselves, in determining the response to chemotherapy.

In statements to the Science Media Center Spain (SMC), an independent office that compiles resources that contribute to understanding the scope of many of the discoveries, Joan Albanell, head of the Department of Medical Oncology at the Hospital del Mar in Barcelona, ​​assessed that the study describes the mechanisms that cause this tumor resurgence in breast cancer and that can be counteracted pharmacologically at an experimental level.

Albanell has stressed that the clinical translation of this discovery is still a question, and has corroborated that the methodology that the researchers have followed is appropriate.“but limited to preclinical models so its translation to the clinic remains to be determined.”

Also in statements collected by the SMC, Javier Cortés, director of the International Breast Cancer Center of Barcelona and senior clinical researcher of the breast cancer research program at the Vall d’Hebron Institute of Oncology, has observed that cancer “it is a whole” and there may be a negative interaction with one part and a positive one with another and the absolute final balance may be positive.

Cortés recalled that there are studies that have compared the advantages and disadvantages of giving or not giving taxanes (a type of chemotherapy). “and the benefits in favor of giving them are very clear.”

Source: EFE